Skin burning treatment



June 2, 1953 F. s. STOUT SKIN BURNING TREATMENT Filed Oct. 3, 1950 I Inventor; F. Sturgis S tou t MJMM his Attorney of frequent replacement,

Patented June 2, 1953 UNITED srAras PATENT OFFICE 6 Claims.

This invention relates to the treatment of skins by burning.

The finishing of the undressed flesh surfaces of skins, hides and the like, hereafter termed skins, and particularly of kid skins, has long presented a problem. In its solution, the tanning industry has heretofore resorted to buifing by abrasive buffers of various sorts, followed by brushing, usually by a rotary brush, to remove the crocking or residue of fibre particles and color. The buffers employed in the bufling stage utilize sandpaper or like abrasive as their bufiing medium. The limitations of such abrasives, both in unevenness of wear and in necessity have rendered it extremely difiicult to buff a skin uniformly and have given rise to high cost both in operation and maintenance. Additionally, the abrasive has a tearing action on the skin fibres, thereby leaving a surface which becomes uneven on subsequent brushing. The bufiing stage also presents conburning off the crocking.

It is, therefore, the primary object of the present invention to provide a process for treating skins by flame, wherein an exposed surface of a skin is heated substantially to combustion temperature under controlled conditions with improvement in both the efficiency of processing and quality of the product.

Another object of the invention is to provide an improved process for finishing an undressed flesh surface of a skin, wherein by controlling burning of the skin and the surface is rendered smooth and even and its color is intensified.

Other objects and advantages of the invention will appear hereinafter in the detailed description, be particularly pointed out in the appended claims and illustrated in the accompanying drawings, in which:

Figure 1 is a side elevational view of the flame treating apparatus embodying the invention;

Figure 2 is an end elevational view of the apparatus of Figure l; and

Figure 3 is a fragmentary vertical sectional view on an enlarged scale, taken along the lines 33 of Figure 2.

Referring now in detail to the drawings in which like reference characters designate like parts, the processof the present invention are adapted for finishing the undressed flesh surfaces or faces of skins, and particularly designed for the suede surfaces of kid skins.

In carrying out the invention, a skin with its,

flesh or suede face or surface up or exposed die or coloring.

is brought under a burner to which it is presented under suflicient temperature and for a sufficient time interval to carbonize the projecting ends of the fibres by burning or singeing, without damage to the skin. Due to the thinness of the suede surface, it is necessary that the singeing be carefully controlled to prevent charring of the body of the skin. Even despite such control, it has been found that the edges of a skin tend to curl up, apparently due to a drying action of the flame, and that any rough or jagged portions of these edges may smoulder as an aftermath of their exposure to the burner. To prevent such charring of the body of the skin by smouldering, with consequent impairment of its value as a whole skin, it will usually be desirable to make provision for smothering any smouldering areas by passing the skin through a suitable smotherer, such as a pair of rollers or a nitrogen mask, or if the operator is experienced, resort may even be had to extinguishing the smouldering areas by hand.

On examination of the skin subsequent to singeing, it is found that the suede surface has been singed to a uniform depth and that the ends of the projecting fibres are rounded and not rough and uneven, as when buffed by an abrasive, thereby presenting a smooth, even surface. In addition, the coloring or colorcharacteristics of the skin are developed or intensified by the treatment to an extent not heretofore obtainable.

After the singeing, there will remain on the sueded surface a charred crocking in the form of minute carbonized particles of fibre and To remove this cracking, the skin is brushed, usually by a rotary brush such as now generally used in conjunction with abrasive bufiing. However, unlike the excess matter left by bufling, the carbonized particles are not subject to a static charge. They, therefore, are readily brushed from the suede surface of the skin and, having no tendency to be attracted to the brush, cannot be redeposited on the same or a subsequent skin.

In the accompanying drawings, there has been illustrated a preferred form of apparatus by which the suede or undressed faces of skins of a wide range of characteristics can readily be singed. Since the apparatus previously described for processing a skin, subsequent to singeing, is conventional, it has not been illustrated. The singeing of flame buffing apparatus, itself is comprised of a suitable table, frame or' stand I on which is journaled or mounted, adjacent either longitudinal end, a transverse roll 2. Supported on the rollers 2 is an endless belt or conveyor 3, which may be made of canvas having an asbestos-impregnated outer surface to render the conveyor flame-resistant. For driving the conveyor, there is provided a variable speed motor unit, indicated at 4, which for the range of belt speeds desired may be either a D. C. motor or, if direct current is not readily available, an A. C. motor equipped with a vari-pulley or like device (not shown). The motor unit is drivably connected to one of the rollers 2 by suitable means, such as the illustrated drive belt 5 and. drive pulleys 6. On either side of the conveyor 3, intermediate the rollers 2, are a pair of stanchions or uprights 1, which are mounted on and upstand from the table 1 in laterally spaced relation. In the illustrated embodiment, each of these stanchions is an angle iron with one leg 8 disposed normal to the path of travel of the conveyor. These stanchions may be welded or otherwise secured to the table and are preferably connected adjacent their upper ends by a cross-bar B.

Carried by the stanchions, intermediate the cross-bar S and conveyor 3 and disposed transversely of and substantially co-extensive in width with the conveyor, is a burner 10 capable of applying controlled heat to a skin. The illustrated burner is of the gas-fired type in which flame is emitted through a plurality of laterally spaced jets II into a ceramic head or hood '32 having a concave, substantially semi-cylindrical reflecting surface l3 by which the heat of the flame is concentrated over a relatively narrow area longitudinally of the conveyor 3. The jets are connected through a common supporting cross-pipe M to a supply pipe l5, the amount and richness of the gas-air mixture, and thereby the heat, being controlled by one or more control valves It. In addition to the temperature of the flame,

one of the factors controlling the degree of singeing is the distance between or spacing of the burner and a skin carried by the conveyor. Accordingly, provision is made for vertical adjustment of the relative height of the burner, this being accomplished in the illustrated embodiment by slidably mounting the burner-supporting cross-pipe in slotsll interrupting the inner or normal legs 0 of the stanchions, the resultant variation in the length of the illustrated supply pipe being automatically compensated for by an expansion joint l3. Not only is the burner l0 adapted to be moved vertically, but it is also designed to be swung from the operative or conveyor-confronting position of Figure 2 to the inoperative position indicated in dot-and-dash line in Figure l, to permit the treatment to be interrupted at will, as well as. to enable the burner to be preheated in inoperative position. This is accomplished in the first instance by slidably connecting the ends of the cross-pipe M to the stanchions i through journals I9. For swinging or rotating the burner through the are between its vertical and horizontal positions, there is fixed to a projecting end of the cross-pipe M a crank or lever arm 20, the outer end of which is linked to an operating arm or lever 21, the latter in turn having its outer end oscillatably supported on the table l by a supporting arm 22. With this arrangement, the operating arm 2| is made sufficiently heavy to counterbalance the burner and, alone, hole it in horizontal or inoperative position, stops (not shown) preferably being provided to limit the extent of the arcuate movement of the burner.

While any slack in the conveyor 3 may be taken up by longitudinal adjustment of the idler of the rollers 2 relative to the table 1 some sagging of the belt intermediate the rollers is almost inevitable. Accordingly, to fix the clearance between the burner and the skin, once the vertical position of the burner has been set, the burner-confronting portion of the conveyor rides over a back-up roll 23 which has its ends journalled to the stanchion I and preferably is adjustable vertically relative thereto, as through continuations of the slots H, to permit adjustment of belt height relative to the burner.

With the several adjustments obtainable in the structure above described, it is possible to control the duration of the singeing by variation of the speed of the conveyor 3, and by adjustment of the flame and the spacing between the burner 10 and the conveyor, to control the effective heat to which a skin is subjected. Consequently, the apparatus possesses the "aforementioned requisite ability to treat skins of widely varying characteristics. In flame buffing kid skins, probably its widest single held of use, it has been found possible to effectively singe their suede surfaces at belt speeds between 20-100 feet per minute, using flame temperatures of from 750-1500 F. and a spacing between the burner and the conveyor of from 2-5 inches, the interval of exposure for substantially identical skins, of course, being less the higher the effective heat upon the surface.

From the above detailed description, it will be apparent that there has been provided an improved process for burning undressed surfaces of skins, whereby the suede surfaces are rendered smooth, uniform and of intensified color characteristics and the resultant crocking can readily be removed by brushing. It should be understood that the described and disclosed embodiment is merely exemplary of the invention and that all modifications are intended to be included which do not depart either from the spirit of the invention or the scope of the appended claims.

Having described my invention, I claim:

1. A process for treating skins comprising singeing a flesh surface of a skin, and removing the carbonized residue therefrom.

2. A process for treating skins comprising singeing a flesh surface of a skin, and brushing the carbonized residue therefrom.

3. A process for finishing skins comprising singeing an undressed flesh surface of a skin, smothering any burning portions thereof, and removing the carbonized residue therefrom by brushing.

4. In a process for finishing skins, the step comprising singeing an undressed flesh surface of a skin.

5. A process for treating skins comprising moving a flesh surface of a skin relative to a burner at a linear speed of from 20-100 feet per minute, at a flame temperature of between 750-1500 F., and at a spacing between said surface and said burner of from 2-5 inches.

F. STURGIS STOUT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,047,211 Halsey et al Dec. 1'7, 1912 2,017,055 Doulette et al. in... Oct. 15, 1935 2,111,610 Boothroyd Mar. 22, 1938 

